JP5317422B2 - Motor control device, motor control method, and electric vehicle - Google Patents

Description

  The present invention relates to a motor control device, a motor control method, and an electric vehicle.

A switched reluctance motor (hereinafter referred to as an SR motor) includes a rotor having a salient pole structure and a stator, and energizes a coil wound for each pole of the stator to generate a magnetic force, thereby rotating the rotor. It is driven to rotate by attracting the salient poles.
Here, when controlling the SR motor so that its output is maximized, the energization switching timing is determined based on a preset advance angle, and the duty is set in accordance with the target torque and the rotational speed. For example, in the control method disclosed in Patent Document 1, a current map memory is provided so that a current target value can be obtained by searching with a target torque and a rotational speed.
Japanese Utility Model Publication No. 6-25224

However, in the conventional control method, a substantially constant value is used for the advance angle, and even when the advance angle is changed, the advance angle is only changed stepwise according to the magnitude of the rotational speed. Furthermore, since the setting of the advance angle and the setting of the duty (current target value) are performed independently, the SR motor is not always operated under the most efficient conditions. For this reason, when the SR motor is used in an apparatus having a limited power source capacity such as an electric motorcycle, it has been desired to optimize the motor efficiency.
The present invention has been made in view of such circumstances, and a main object thereof is to improve motor efficiency.

The invention according to claim 1 of the present invention for solving the above-described problem is a case where the advance angle when the timing for switching the energization of the motor is calculated with respect to the combination of the target torque and the rotational speed is energized in the coil of the motor. Associating the advance angle control map in which the advance angle changes stepwise according to the associated target torque as the value of the state where the duty is set to 100%, the duty when the motor is energized with respect to the target torque and the rotational speed, advancing a duty control map duty is obtained as a torque obtained in advance selected by the angle control map for adjusting the target torque, based on the advance angle control map and the duty control maps, depending on goals torque gradually changing the advance Te, and having a control unit for changing the duty according to the target torque motor And a control device.
The motor control device controls the advance angle and the duty in accordance with the target torque and the rotational speed. The duty value is changed so that the torque obtained when the energization control is performed at the advance angle determined by the advance angle control map matches the target torque.

According to a second aspect of the present invention, there is provided a motor control device according to the first aspect, a grip that is a target torque input means that is rotated by a driver, and a drive wheel that is rotated by the motor. An electric vehicle having a rotation detection sensor for detecting the number of rotations.
This motor control device captures the amount of grip operation by the driver as a target torque, and the rotational speed is measured by a rotation detection sensor. The advance angle control and the duty control are performed according to the target torque and the rotational speed obtained in this way.

In the invention according to claim 3 of the present invention, the advance angle when calculating the timing for switching the energization of the motor with respect to the combination of the target torque and the rotational speed is set to 100% the duty when energizing the coil of the motor. The advance angle control map in which the advance angle changes stepwise according to the associated target torque as the value of the related state, and the duty when the motor is energized with respect to the target torque and the rotation speed are selected in the advance angle control map Based on a duty control map that obtains a duty that adjusts the torque obtained by the advanced angle to the target torque, it is information on the operating point consisting of the target torque and the rotational speed , and the advance angle is stepwise according to the target torque. It is varied, by varying the duty according to the target torque, switching the energization of the motor at the operating point timing The step of determining the advance angle when calculating the motor and the duty when energizing the motor at the operating point is adjusted so that the torque obtained when operating at the determined advance angle matches the target torque. The motor control method includes a step of determining a duty, and a step of performing energization control of the motor based on the determined advance angle and the duty.
The motor control method controls the advance angle and the duty according to the target torque and the rotational speed by executing the step of determining the advance angle and the step of determining the duty. Either the step of determining the advance angle or the step of determining the duty may be performed first.

  According to the present invention, since the advance angle and the duty are controlled according to the target torque and the rotational speed, the target torque can be increased or decreased by changing the duty without changing the advance angle as in the prior art. Compared with the case where it was made to operate, the operating efficiency of a motor can be improved.

The best mode for carrying out the invention will be described in detail with reference to the drawings.
FIG. 1 shows a schematic configuration of an electric motorcycle as an example of an electric vehicle using an SR motor.
In the electric motorcycle 1, a front wheel 4 is supported by a front fork 3 that is rotatably supported by a vehicle body 2, and the front wheel 4 can be steered by a handle 5 provided at the upper end of the front fork 3. A seat 6 on which a driver is seated is attached to the vehicle body 2, and a rear wheel 7 that is a driving wheel is rotatably supported. The rear wheel 7 incorporates an SR (switched reluctance) motor 8 and is driven to rotate by an output from a control device 10 fixed to the vehicle body 2. An output of an accelerator grip 11 provided on the handle 5 and an output of a rotation detection sensor 12 that detects the rotation of the rear wheel 7 are connected to the control device 10.

  The SR motor 8 is an outer rotor type in which a rotor 22 is rotatably supported on the outer periphery of a stator 21 fixed to the vehicle body 2 side. The stator 21 has a plurality of 24 salient poles 23 provided on the outer periphery at regular intervals. A coil 24 is wound around each salient pole 23. The rotor 22 has 16 salient poles 25 projecting at equal intervals on the inner periphery.

  The control device 10 includes an inverter 32 that outputs a current to the coil 24 of the SR motor 8 when a DC voltage is applied from the battery 31, and a control unit 33 that controls the inverter 32. The control unit 33 includes a microcomputer, and has a configuration for switching ON / OFF of the switching element of the inverter 32 based on the output signal of the accelerator grip 11 and the output signal of the rotation detection sensor 12. Further, the control unit 33 is provided with an advance angle control map 35 and a duty control map 36, and the advance angle and duty can be controlled.

  As shown in FIG. 2, the advance angle control map 35 is configured such that the advance angle is determined in one way for the combination of the rotation speed and the target torque. The advance angle control map 35 is created by examining the advance angle at which a specific target torque can be obtained at a specific rotation speed when the SR motor 8 is rotated at a duty of 100%. For example, when the rotational speed is zero, the advance angle decreases stepwise as the target torque increases. On the other hand, in the region where the rotational speed has increased, the advance angle gradually increases as the target torque increases even at the same rotational speed. At the same target torque, if the rotational speed is in an area greater than zero, the advance angle increases as the rotational speed increases.

  As shown in FIG. 3, the duty control map 36 is configured such that the duty is determined in one way for the combination of the rotation speed and the target torque. The duty control map 36 is created by examining the relationship between torque and duty for each rotation speed, and is configured so that a duty is obtained such that a target torque can be obtained at an advance angle determined by the advance angle control map 35. ing. For example, in the region where the rotational speed is zero, the duty decreases as the target torque decreases. In the region where the rotational speed is greater than zero, the duty increases or decreases as the target torque increases.

The accelerator grip 11 shown in FIG. 1 is provided on the handle 5 so that the driver can rotate it, and a signal corresponding to the operation amount is output to the control device 10. Information on the operation amount of the accelerator grip 11 in the electric motorcycle 1 is handled as a target torque. That is, the target torque value increases in proportion to the rotation amount of the accelerator grip 11.
The rotation detection sensor 12 may have any configuration as long as it can detect the rotation speed of the rear wheel 7. When the in-wheel motor type electric motorcycle 1 transmits the rotation of the SR motor 8 to the rear wheel 7 without decelerating, a rotary encoder that detects the rotation of the rotor 22 can be used.

Next, a method for controlling the SR motor 8 will be described.
When the driver rotates the accelerator grip 11, information on the operation amount is input to the control unit 33 of the control device 10. Further, the output signal of the rotation detection sensor 12 is also input to the control unit 33. The control unit 33 calculates the target torque from the operation amount of the accelerator grip 11 and calculates the rotation speed from the output signal of the rotation detection sensor 12. Then, the advance angle is determined by searching the advance angle control map 35 with the combination of the target torque and the rotational speed (hereinafter referred to as the operating point). Similarly, the duty control map 36 is searched at the same operating point to determine the duty. As the advance angle at this time, a value is selected that enables efficient energization switching at the operating point. Further, the duty adjusted so as to obtain the target torque at the selected advance angle is selected.

For example, consider a case where the target torque is reduced by reducing the amount of rotation of the accelerator grip 11 when the target torque is achieved when the duty is set to 100% with the advance angle extracted from the operating point. When the amount of decrease is small, the same advance angle as before the decrease can be obtained by searching the advance angle control map 35. On the other hand, a duty lower than 100% is obtained as a search result of the duty control map 36. Thus, in the region where the amount of decrease is small, the duty is changed without changing the advance angle.
As the amount of decrease increases, the value of the advance angle obtained when searching the advance angle control map 35 decreases. From the duty control map 36, a duty is obtained such that a target torque is obtained when the vehicle is operated at a reduced advance angle. Thus, in the region where the change is large, both the advance angle and the duty are changed.
Even when the target torque increases, the advance angle and the duty are appropriately changed according to the search results of the maps 35 and 36 as in these processes. Since the duty control map 36 is created in consideration of the change in the advance angle, either the search of the advance angle control map 35 or the search of the duty control map 36 may be performed first.

  The control unit 33 determines the energization switching timing according to the advance angle determined by the map search, and outputs a drive signal to the inverter 32 so as to have the duty determined by the map search. The inverter 32 controls energization to the coil 24 of the stator 21 and rotates the rotor 22. Then, the rear wheel 7 fixed integrally with the rotor 22 rotates.

  In this embodiment, an advance angle control map 35 and a duty control map 36 are provided in the control unit 33 to determine an advance angle at which the most output can be obtained by a combination of the rotational speed and the target torque, and to change the duty by changing the duty. Since adjustment is performed so as to match the torque, motor efficiency can be easily optimized. By using such a system for the electric motorcycle 1, efficient driving becomes possible.

  Here, Table 1 shows the results of measuring the efficiency of the SR motor 8 in this embodiment. The SR motor 8 used for measurement uses a stator 21 having 24 poles and a rotor 22 having 16 poles, and the load is changed in four ways of 9.5 Nm, 13.4 Nm, 17.3 Nm, and 21.2 Nm at 400 rpm. The motor efficiency in each was measured. Table 1 also shows the results of examining the motor efficiency of a conventional control device as a comparison.

In the conventional control device, the advance angle is fixed, and the duty is gradually increased as the load increases. On the other hand, in this control apparatus 10, even if the rotation speed is the same, different values such as advance angles of 2 °, 3.5 °, and 5 ° are selected depending on the load. Under the load conditions from the lowest load to the third, the motor efficiency is improved as compared with the conventional control device by simultaneously controlling the advance angle and the duty to optimize the two. Under the fourth load condition, the same lead angle and duty were obtained as a result, so there was no difference between the two. Note that the duty is 100% in the control by the control device 10, but if the load value is different, the duty value may be different even at the same rotational speed.
Further, in the conventional apparatus, the advance angle is fixed, and the duty is gradually increased every time the load increases. Therefore, the operation amount of the accelerator grip is set to the duty. On the other hand, in this embodiment, the operation amount of the accelerator grip is handled as the target torque, so that the duty can be adjusted and the driving efficiency can be improved.

Note that the present invention can be widely applied without being limited to the above-described embodiment.
For example, the numbers of poles of the stator 21 and the rotor 22 of the SR motor 8 are not limited to those illustrated.
A torque sensor or a current sensor such as a shunt resistor provided in the inverter 32 may be provided, and by inputting such information to the control unit 33, a further optimal advance angle and duty may be calculated.
The system using the control device 10 is not limited to the electric motorcycle 1. Other vehicles may be used.

1 is a block diagram of an electric motorcycle showing an example of a system including a motor control device according to an embodiment of the present invention. It is a figure which shows an example of an advance angle control map. It is a figure which shows an example of a duty control map.

Explanation of symbols

1 Electric motorcycle (electric vehicle)
8 SR motor 10 Control device 11 Accelerator grip 12 Rotation detection sensor 35 Advance angle control map 36 Duty control map

Claims (3)

Depending on the target torque associated with the value of the state in which the duty when energizing the coil of the motor is set to 100%, the advance angle when calculating the timing of switching the energization of the motor with respect to the combination of the target torque and the rotational speed An advance control map in which the advance angle changes stepwise ,
A duty control map that associates a duty when energizing the motor with respect to the target torque and the rotational speed, and obtains a duty that adjusts the torque obtained at the advance angle selected in the advance angle control map to the target torque;
Based on the advance control map and the duty control map is changed stepwise advance angle in accordance with the objectives torque, and a control unit for changing the duty according to the target torque,
A motor control device comprising: A motor control device according to claim 1;
A grip that is an input means of the target torque and is rotated by the driver;
A rotation detection sensor that detects the number of rotations of a drive wheel that is driven to rotate by the motor;
An electric vehicle comprising: Depending on the target torque associated with the value of the state in which the duty when energizing the coil of the motor is set to 100%, the advance angle when calculating the timing of switching the energization of the motor with respect to the combination of the target torque and the rotational speed The advance angle control map in which the advance angle changes stepwise, and the duty when the motor is energized to the target torque and the rotational speed are related, and the torque obtained by the advance angle selected in the advance angle control map is the target torque. Based on the duty control map that provides the duty to be adjusted to, the operating point information consisting of the target torque and the rotational speed , the advance angle is changed stepwise according to the target torque, and the duty according to the target torque by varying the, to determine the advance of the time for calculating the timing of switching the energization of the motor at the operating point And the step,
Determining the duty to be adjusted so that the torque obtained when the motor is operated at the determined advance angle and the target torque are matched as the duty when energizing the motor at the operating point;
Performing energization control of the motor based on the determined advance angle and the duty;
A method for controlling a motor, comprising:

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